Electrical condenser



. w. DUBILIER .Filed May 24 Marh 2 1.926.

' ELECTRIGAL CQNDENSER To all whom t may concern:

Patented Mar. 2, 1926.

EIEGTRICL` Applicaties. 1aed nay 24,

Be it known that I, WILLIAM DB New York, in the county of New York Stateof New York, vhave invented 4a certain ffn'ew. and useful ElectricalCondenser, of

which the following is a .specificatio1`1 .v

The invention has for an object to provide an electricalcondenserinvolving the'use 0fbut a".rel.atively small quantity ofdielectricand conducting material, and of simple.

structure, which nevertheless will be caand high frequencycircuitswithout the production of undue vresistance losses,;brushd1s-.

charge, heating'or other undesirable eifects' tending to injurel ordestroy the'Sme.

Further objects and advantages of the invention will be in part-'obviousand in part specifically pointed out" in the description hereinaftercontained, which', ltaken'in c0n.

fnectionwith the accompanying drawings, 1

discloses a preferred 'embodiment thereof;l such embodiment, however, isto be con-1 sidered merely .-as lillustrative ofA its prin-l ciple.Inthe drawings:

'Fig. -1 is a'plan vlew of a condenser made in accordanc'e with theinvention held in a i Furthermore, the conducting armatures orfiy'suitable clamp, and in position initsjcasingl Fig..2 is a side-view ofthe structure shown i'n-Fig'. 1, a portion ofthe clampl being cutv awayfor` clearness.4 Y

. Fig. 3 .is a fragmentary sectional '.Yiew showing a form' of tap orllead Which'may be used in connection with the condenser.

'i Fig.v 4 is a section on line 4-'4of Fig. 2. Vhen condensers aredesigned for use in high potential or. high frequency circuits, it isdesirable to bring about' a subdivision of.

lthe potential betweendiiferent .parts ofthe condenser, in 'such mannerthat the strain at any given' partwillbe reduced-'sufficiently ltoenable the; condenser to stand long continued' use -Without unduedeterioration due to brush discharge, heating, or other causes.

plates of condenser should be capable of carrying the current for whichit is designed, without the production of sufficient heat to injure thecondenser; in other words, the con ducting plates should beef relativelylow resistance.- :l l

` -If a .condenser of the above character be made up by constructingcondenser sections @1,575,044 ,'1ffulsu-TEDl STATE-s lIAATENT OFFICE.

WILLIAM DUEiLIEE, or NEW Yonx, N. Y., AssIGNoR To DUBILIEEQONDESEE &

, RADro CORPORATION, A coREoEA'rroN 0F DELAWARE.

CONDENSER.

.having a plurality of conducting;y plates of a bpposite polarityinterleaved with dielectric' citizen ofthe United States, re'sidin'g'.att

ofA such sections, it is Anecessary. `to employ several conductingsheets in each section to give the section sulcient thickness. and

1 strength to be handled without `too .great risk of injury; also thecurrent travels through the' connected sections inthe plane oftheconducting plates, or 'through the sheets from. end toend,`thus-'following a further .reason a substantial number of sheets in''parallel are usually neededfin each section pathof high resistance, sothat, for this` pable of withstanding use in high .potential to reducevthe internal resistance `of theconi denser' toa valuev low enough t0prevent g A heating to an'lndesirable degree.

From the aboveand other considerations .it may, result, particularlywhere'tcondensers .of klow capacity are desired, that individualsections of the character` above described necessarily will have suchlarge capacity,v that an unduly large number ofsuch sections.

will have to-be connected in seriesJ to reduce the capacity' ofthecomplete condenserto the desired value and yet retain .suliicientconductivity "in the plates. Thus. the condenser becomes .of large size,andinvolves increased expense on account of the amount of -dielectrlcand conducting material used, and. the .added labor of preparing andprop- 'e1-ly 'assembling the saine.

` According tothe present invention, the conducting plates ofl thecondenser are s0 larranged that the current 'iows transversely throughthe same, instead offfrom end to fend, thus greatly reducing thelengthof the.

'path of current travel `and in crea'sing vthe Vcross-section ofconductor; therefore the ,c a- I pacity ofl the-unitelements of thecondenser may be made much smaller, and a Sina-ller..

nuniber of unit elements in series employed, without encountermg thetrouble of to much reduced conductivity.

V74Referring to Figs. 1 and 2, the condenserbe made up` of a lpluralityof conducting plates l, preferably' of soft metalsuch as tin foil cutinto rectangular form, and

interleaved with larger '-dielectric sheets 2 whit-h1 prefer to make .ofsheet mica, and

built up into a s tack. Circuit is made to 'the plates 1 which are atopposite ends of a series, and the intermediate plates. are completelyinsulated, so that the dielectric sheets 2 may be permittedto overlapsuch plates 'of a vacuum, after which lthe stack should on all four.sides. plates act as 'floating capacities between the eral tons, topress out substantially all the end plates, and the'total potentialwillbe insulating compound -fron'i between the condivided between allthe plates, each pair of ducting plates and'. dielectric sheets, andadjacent plates acting as a unit condenser. birng about an intimatesuriacecontact be- The currentpath is in a direction transverse t veenthe same.

length of the path of current travel is a very .small capacity aredesired such as ,may

Thus the intermediate be placed under a high compression of sevto theplane of the plates, ,and the cross-Di Insome instances condenser stacksof the section of the conductive-path equals, theV `liaractcr abovedescribed may be made up length of the plate multiplied by its Width, inone or more groups of standard sizes coninstead of the width of theplate multiplied taining convenient numbers of co1idei.ser., i by its`thickness; the increased conductivity units in series, and several suchstock eonmay be compared to what would be obtained denser staekscombinedin series or parallel bypassing current across an extended con- 'to makeup a desired condenser. For exductor, instead of along its length. Alsothe ample, where high potential condensers of function of the thicknessof the plates, in- 'be sed with radio sets of the vacuum tube safe, andeach additional' sub-division of plurality of taps Vvoltage involvesonly one; additional conthe several groups 3 to 6 and thus, by maksteadof their length. With the condenser typ ,several standardgroups may beplaced constructed in the above manner, the interend\to end, thusforming a composite block nal resistance therefore is exceedingly low,containing a. proper number of unit conand it is not necessary to use alarge amount dciiseisin series andhaving the desired low of conductingmaterial with the added dicapacity. The form of condenser illustratedelectric sheets .Which-would be required, to consist-soi :i,pluralityot' series groups 3, 4;,

carr the current?. Thus only that n umber fand (3 which may be of thesame or dilierof p ates in'series need be used which is con` entindividual capacities, asf desired, and

sidered necessary to reduce the voltage per any desired .nuinbermayb'eeinployed to' unit condenser to'a valucwhich is'considered build up'completewstackf' s shown, a

ducting plate, and one dielectric sheet. ing the eirciiit connections todiderent taps, The required capacity and the potential different'capacities may be obtained. The of the circuit in which the condenseristo taps 7 conveniently may' be made in the be used being known, thenumber of unit torni of copper strips overlapped by the di. condenserslnecessary to be connected in electric sheets l on three sides, butprojectlunit condensers.

`series may be selected, and a size of coning beyond the latter on thefourth side, and

ducting plateadopted which will give applates 8.0i tin foil, 'similar tothe plates preproximately thel desired capacity when th e viouslydescribed, may be placed on opposite selected number of unit condensersare sides otftaps 7-to facilitate the making of an placed in series.-Then by adding or removintimate Contact' between the conducting ingoneor more conducting plates, 'if necesiiiatei'ial associatedwith taps 7and adjacent sary, the final capacity may be brought dielectric sheets2. Thus the taps need..not

'within the'required limits, without unbalrenderthe stack loose orotherwise defective ancing the distribution of potential over the at thepoints from which they lead.

The condenser should be securely clamped The number of unit condensersemployed to insure that the sheets will be held j in Seriesiorany givencondenser, should be throughout in intimate surface contact asl v suchas to reduce the potential per unit conmentioned above, after thecondenser has denser to a value below the brush discharge vbeen put intoactual use. point. I prefer to employ as the dielectric, According tothe present invention, I

.unitary mical sheets averagingabout threeplace the stack within acasing 9, preferably thousandths of an inch in thickness, in of metal,with the sheets making up the" which casethe potential per unitcondenserl Stack disposed'substantially parallel to the .shouldnot riseabove a value'in the neighend wall of the casing, the taps 7projectborhoodv of' 1000 or 1500volts maximum, .ing upwardlytoward theopen side ofthe and in certain cases, particularly where the Casing!/Thus one or more terminal conneccondenser is to be subjected toundamped tionsl orthe condenser may be led through oscillations, Iprefer to reduce the potential the cover 10 of the casing in anylsuitable to a value around 600 or 800 volts maximum. manner (not shown)to connect with the.

Furthermore, in order to elimiifatel air, taps, Thecondenser'issurrounded by 'clamp vacua moisture, etc., and. to renderthe diil which fits within the side walls of casing electric ashomogeneousl as possible, I prefer 9,. and thus the condenser may beassembled to impregnate the condenser thoroughly intoproper positionwithin'the 4clamp and with a heated insulating composition such thelatter inserted into or withdrawnv from as melted paraffin, or othersuitable Acomthe casing Without disturbin the stack. pound, and subjectthe` same to the action The clamp consists of the bearing members areinterposed between.

ics 1 12 and at opposite ends of vthe stack, and

the tension members 14 extend between the.A

' bearin members to transmit the strain from one en of the stack to theother; I prefer to make up the clamp from one 'contlnuous piece of metalsuch as spring steel, which may be drop-forged, punched or pressed intoproper shape. The bearing block may then `be interposed between onebearing member 13 and the adjacent end of the stack, and the compressionapplied to the stack at .-1 point substantially in line with the centrei by means of a-binding member such as the vstud 16 threaded throughbearing member 18V and pressing on, block 15. Thus the block 15 willexert substantially-uniform pressure `'upon the stack throughout theentire area and will not tend to bow o warp. The o posite bearing member1 may be' mage heav enough to insure that its surface whic lpressesagainst the stack will `besubstantially Hat. With proportions similar to4those shown in the drawings, the bearing member 12 will be relativelyrigid, and any changes in shape in the clamp which may occur due tothespringiness of the material,

' when stud 16 is tightened up, will `ake place in its thinnerportions,particularly wthere tension members v14 join on to the bearingAso member 13, without alfecting the 'condenser stack detrimental-ly.

`Vihere the stack is combined with a clamp of the above character, theclamp or the casing or both may lform one terminal of the condenser, orthe clamp'may be completely -insulated,if desired. It willbenoted thatthe clamp acts to bridge' electrically the space-between the groups 3and V6, and thus i1' the taps 7 at opposite ends of group 4 areconnected to' opposite` circuit terminals,-

:groups 3, 5 and gwillibe in parallel with group 4 between theterminals. This arrangement maybe adopted to give a relatively largecapacity,"or, 1f .desired the sections 3, 5 and fmayin-clude such'lar enumbers of unit condensers in series that t e capacity 'of groups 3,'and G .inseries is negligible as compared to the. capacity of group 4,so

that the resultant capacity is substantially that of. group 4 alone.Similarly thenumber of. unit condensers inseries in group 4 may -be solarge. as compared to groups `3, and 6 that the capacity of group 4 maybe 'disregarded, thenumber of unit condensers 4in the different groups 3to' as illustrated not beingin any way essential.

lIn mounting thecondenser. stack and its slamp within-the casingSLI-prefer to place struct the cover 10 `of mica sheets impreg` natedwith' anl insulating compound such as the clamp parallel to the bottom of the cas-- ingin such manner that taps 7 wlll project upwardly towardthe cover 10. Partlculai-ly where the condenseris to be subjectedtoundaniped oscillations, I prefer .to conparaiin, and pressed togetheras closel possible to form a homogeneous sheet w ich may be suitably`held in position over the casing 9 as by means of a metal ring 17 andscrews 18 which clam the cover lbetween such ring and a should the upperedge of the casing.

In order to facilitate the positioning" of the clamp andcondenserstackwithin the" casing, the cla-m may be attached to the coverbefore the atter is aiiixed to the casing; this is accomplished in thepresent instance by a pair of straps 20 of thln metal or the likesecured tothe under side of the cover by means of screws 21, and to theclamp by further screws 22. Thus the condenser clamp and stack may bepositioned properly with respectto the cover, and when the latter issecured to the casing 9 the condenser stack will be properly located inthe casing without further adjustment. Ordinarily the casing'will-befilled with insulatingcompounds such as paraffin, and the straps 20thusserve to hold the 'condenser in sus 'nsion' in the insulatingcompound until the latter solidilies. In cases where the casing or-clampare included in circuit with the condenser stack, the straps 20 also mayact as circuit connections thereto.

While a specic embodiment of the invention has been described, 1t willbe obvious that many changes may be made therein without departiiivention as defined I claim: 1.,- An electrical. condenser comprising astack havingv a series of conducting sheets alternating with larger thinand unitary from the spirit of the indielectric sheets,.the respectiveseries .of sheets above mentioned being disposed substantial'- ly inline, with each conducting sheet overlapped on all sides 'by theadjacent dielecin the following claims.

er. 19 running around tric sheets, and the conducting sheets being sheetto afvalue below. the brush discharge 2. An electrical condensercomprising a stack having a series of conducting sheets alternating withlarger thin and unitary dielectric sheets, the .respective series of.-sheets above mentioned bemg disposed substantially in line, witheach-conducting sheet overlapped on all sides by the adjacent dielectricsheets, and the conducting sheets being all electrically isolated, ametallic clamp surroundingsaid stack and compressing its opposite-ends,and circuit connections being made to points along the `stack which l'avoid liighstrainsvbetween the clamp. and 'the respectiveend sheets ofthe stack.

3. An electrical condenser comprising a stackfhaving a series ot'conducting sheets alternating with larger `thin and unitary dielectricsheets, the respective series ot sheets above mentioned being disposedsub?. stantially' in line, with each conducting sheet overlapped on allsdes by Ythe adjacent dielectric sheets, and the conducting'sli'eetsbeingv allA electrically isolated, conducting plates being 'disposed' atspaced intermediate pointsfilong the stack and having opposite' circuit2connections leading thereto, and a metallic .clamp siii-rounding thestack,

ylereby tlie isolated sheets between the c onducting plates are inparallel with the iso-V lated 'sheets which are between the respectiveconducting plates and the ends of the stack.

4. An electrical condenser comprisingY a stackv having aplurality otseries of con ducting sheets alternating with larger thin and unitary'dielectric Sheets, the respective lconducting and dielectric sheets ofsaid series .being disposed substantially in line with each conductingsheet 'overlapped on all sides by the 4adj acent dielectric sheets andthe conducting sheets being all electrically isolated,

a conducting plate interposed between ad`- jacent series 'of sheets,said conductingplate having a circuit connection leading thereto,

and a metallic clamp -compressingsaid stack,

theclainp being in good conductive relation to the respective endisolated sheets of said y stack.

5. An electrical condenser mnade otdielec'- tric sheets andconductingplates in intimate contact with each other, all the conductingplates having about the saine surface area and some being isolated` aclamp maintain- 'ing all said sheets and plates under pressure,

and a terminal interposed Within the stack i of plates.

, 6. An electrical condenser made o f dielectric sheets andconductingplates, said sheets and plates in intimate contact with eachother, all the conducting plates having about the saine surface area,and some being isolated, and a terminall interposed within the stack ofplates and connected in an electric circuit., N

A7. An electrical condenser made of dielecducting plates having aboutthe same surn `face area and some being isolated, aclamp maintaining allsaid sheets'and plates under pressure, and terminals interposed invarious positions Within the stack 'of plates.`

8. An electrical condenser made of dielectric sheets and conductingplates, said sheets and plates in intimate Acontact with each4 v other,all the-conducting plates having about "4 y l 'j 1,575,044-

lated,v and terminals interposed iii various positions within the stackof plates and con nected in an electric circuit.

9. Ain electrical condenser comprising a'.

casing, stack ot" unit condensers contained therein, said units beingarranged in series,

a clamp 'for said stack comprising an inte` gral metallicv membercontained Within the casing extending entirely around lthe stack,and-means associated vWith said metallicV ineinber ior exertingcompression on the;

stack.

l0. .in .electrical condenser comprising a jcasing, a stack ot unitcondensers contained "tlierein,.a clainp for said stack comprising amember contained Within the. casing and extending around thev stack,ineansjassociatedwith said clamp forj exerting compression on the stack;and means electrically connecting the end units to'said clamp member.11. An lelectrical condenser comprising a casing,a stack of unitcondensers contained therein, said units being connected in series, aclainp extending entirely around the stack, means associated with saidclamp. for

exerting compression oii thel stack; a connectio'ii'betiveen the ends'ofsaid stack and said clamp, and terminals extending from said 12. .Anelectric condenser made up of thin mica sheets interleaved with'conducting plates, terminal connections leading respectively toconducting'plates which yaIe-sepaf` rated by 'aseries of otherconducting lates,

the adjacent plates of said series di ering; progressively/'in potentialfromone terminal 13. An electrical condenserfcomprising aY plurality ofinsulating and conducting sheets divided into a plurality of sections,each secing a plurality of conducting plates having .tion forming a unitcondenser and compristerminals and a plurality of conducting.

plates isolated from each other and thel l plates with terminals,connectionsfbetween said unit condensers whereby the same are' arrangedin parallel circuit with the main connections to the condenser.

lien electric lcondenser comprising a metallic casing, a-stack of unitcondensers containedtherein, a clamp for said stack' interposed betweenthe same and the casing,

a sheet -mica cover for the casing, and means l'or suspending thecondenser stack and clamp from said cover. lo. An 'electric condensercomprising a metal casing, a stack rit/unit condensers con-V tainedWithin said/casing with the laminations4 of the 'stack dis osedsubstantially parallel` to lthe side wal s thereof, a clamp for theAcondenser stack inter osed between tliesanie and the side walls o thecasing, a

sheet mica cover extending across the'open side of the casing, and aplurality of metal straps Isecured to said cover and to said clamp forsuspending the `stack and clamp n 'from the cover. e

16.. An electric condenser made up of thin unitary sheets of micainterleaved with conducting plates, the mica sheets overlapping saidplates on all sides, and terminal connections ybeing provided tocertainof said con` WILLIAM DUBiLIEn.l

